CONFIG: putc - out of clists

CONFIG: putc - out of clists

Post by pc_wil.. » Fri, 04 Aug 2000 04:00:00



Newbie question. Running SCO Openserver 5.0.5. Of late we have been
receiving the following message on the server screen on an almost daily
basis:

CONFIG: putc - out of clists...

The only solution seems to be to hit the power button. Can't get to a
login prompt to shutdown gracefully.

After a search around the internet I thought I'd found the solution -
run ./configure and increase the NCLIST and TTHOG parameters which I
expected would be set quite low. However NCLIST is currently set to 712
and TTHOG is 5120.

We have 10 Wyse terminals (9600bps), 3 serial printers, and 10 PCs
running terminal emulation software over fully port switched 100Mbps
ethernet.

Any advice on how to solve this problem would be much appreciated.

Cheers,
Phil.

Sent via Deja.com http://www.deja.com/
Before you buy.

 
 
 

CONFIG: putc - out of clists

Post by Jean-Pierre Radle » Fri, 04 Aug 2000 04:00:00



| Newbie question. Running SCO Openserver 5.0.5. Of late we have been
| receiving the following message on the server screen on an almost daily
| basis:
|
| CONFIG: putc - out of clists...
|
| The only solution seems to be to hit the power button. Can't get to a
| login prompt to shutdown gracefully.
|
| After a search around the internet I thought I'd found the solution -
| run ./configure and increase the NCLIST and TTHOG parameters which I
| expected would be set quite low. However NCLIST is currently set to 712
| and TTHOG is 5120.

CLIST buffers are small, maybe 70 bytes each.  Go ahead and increase
NCLIST to a four-digit number.

--
JP

 
 
 

CONFIG: putc - out of clists

Post by Tom Parson » Fri, 04 Aug 2000 04:00:00



| Newbie question. Running SCO Openserver 5.0.5. Of late we have been
| receiving the following message on the server screen on an almost daily
| basis:
|
| CONFIG: putc - out of clists...
|
| The only solution seems to be to hit the power button. Can't get to a
| login prompt to shutdown gracefully.
|
| After a search around the internet I thought I'd found the solution -
| run ./configure and increase the NCLIST and TTHOG parameters which I
| expected would be set quite low. However NCLIST is currently set to 712
| and TTHOG is 5120.
|
| We have 10 Wyse terminals (9600bps), 3 serial printers, and 10 PCs
| running terminal emulation software over fully port switched 100Mbps
| ethernet.

Exhausting clists was quite common on pre-OpenServer system and very,
very UNcommon on OpenServer.

Clists pertain only to the serial ports and you probably have one
or more bad connections/cables.  A loose or defective cable/connector/port
can easily cause enough chatter to cause a clist problem.
--
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CONFIG: putc - out of clists

Post by pc_wil.. » Sat, 05 Aug 2000 04:00:00


Thanks for your speedy replies.

I am concerned that simply increasing the NCLIST parameter will mask
the underlying problem, which I suspect lies with the
cabling/connectors/ports.

Additional Info:
The comms company who did the structured wiring fully tested all the
Cat5 at the time and fixed any problems they found, although I have
since fixed a few popped krones. I assembled the RJ to DB adapters (the
push-pin variety - never could use a soldering iron) myself with only
pins 2,3 and 7 wired.

Any advice on how best to troubleshoot this one would be much
appreciated. Are there any tools/testers available to
detect "chatter"ing terminals?

Cheers,
Phil.



> Newbie question. Running SCO Openserver 5.0.5. Of late we have been
> receiving the following message on the server screen on an almost
daily
> basis:

> CONFIG: putc - out of clists...

> The only solution seems to be to hit the power button. Can't get to a
> login prompt to shutdown gracefully.

> After a search around the internet I thought I'd found the solution -
> run ./configure and increase the NCLIST and TTHOG parameters which I
> expected would be set quite low. However NCLIST is currently set to
712
> and TTHOG is 5120.

> We have 10 Wyse terminals (9600bps), 3 serial printers, and 10 PCs
> running terminal emulation software over fully port switched 100Mbps
> ethernet.

> Any advice on how to solve this problem would be much appreciated.

> Cheers,
> Phil.

> Sent via Deja.com http://www.deja.com/
> Before you buy.

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

CONFIG: putc - out of clists

Post by Tom Parson » Sat, 05 Aug 2000 04:00:00



| Thanks for your speedy replies.
|
| I am concerned that simply increasing the NCLIST parameter will mask
| the underlying problem, which I suspect lies with the
| cabling/connectors/ports.
|
| Additional Info:
| The comms company who did the structured wiring fully tested all the
| Cat5 at the time and fixed any problems they found, although I have
| since fixed a few popped krones. I assembled the RJ to DB adapters (the
| push-pin variety - never could use a soldering iron) myself with only
| pins 2,3 and 7 wired.
|
| Any advice on how best to troubleshoot this one would be much
| appreciated. Are there any tools/testers available to
| detect "chatter"ing terminals?

Admittedly crude but you could selectively disconnect one terminal at
a time.  I *think* the kernel may recover if you remove the offending
device.

--tom
==========================================================================

==========================================================================    

 
 
 

CONFIG: putc - out of clists

Post by Tony Lawrenc » Sat, 05 Aug 2000 04:00:00



> Any advice on how best to troubleshoot this one would be much
> appreciated. Are there any tools/testers available to
> detect "chatter"ing terminals?

I'd look for getty's respawning or other unexpected
activity; a crude off the top of my head script to do that
might be something like:

mkdir /tmp/whassup
for i in /dev/tty[a-d]*
# modify the wildcard to pickup whatever your serial ports
are
do
mkdir -p /tmp/whassup/$i
fuser $i > /tmp/whassup/$i/a 2>&1
sleep 5
fuser $i > /tmp/whassup/$i/b 2>&1
diff /tmp/whassup/$i/a /tmp/whassup/$i/b >
/tmp/whassup/$i/diff
cat /tmp/whassup/$i/diff
done

most of the diffs should have nothing in them unless people
are logging in and out or running new programs.  Anything
that has output can be looked at more closely.

--

SCO/Linux articles, help, book reviews, tests,
job listings and more : http://www.pcunix.com

 
 
 

CONFIG: putc - out of clists

Post by Jeff Lieberman » Sat, 05 Aug 2000 04:00:00



>I am concerned that simply increasing the NCLIST parameter will mask
>the underlying problem, which I suspect lies with the
>cabling/connectors/ports.

Yep.

Quote:>The comms company who did the structured wiring fully tested all the
>Cat5 at the time and fixed any problems they found, although I have
>since fixed a few popped krones.

Oh-oh.  I've found that cabling companies either get it perfect, or
totally*it up, with nothing in between.  If you're finding wiring
or crimping errors, you'll probably find they're epidemic.  You probably
can't afford a cable certifier, but you might consider buying one of the
under $100 testers that check continuity.

Quote:>I assembled the RJ to DB adapters (the
>push-pin variety - never could use a soldering iron) myself with only
>pins 2,3 and 7 wired.

Thank you for *NOT* including the "protective" ground.  That probably
saved you some difficulties.

Pins 2,3 and 7 are all you need if:
1.  You're not using hardware flow control.
2.  You're not using the upper case modem control port names such as
/dev/tty1A.  These will required doing something with Pin 8 (carrier
detect).
3.  You don't have long wires going to pins 5 and 6 which can act as an
antenna and pickup crud.
4.  Your unspecified smart serial port vendor isn't a really ancient
Digiboard Com8i that doesn't "float" the inputs high and require that all
inputs (pins 4,6,and 8) go somewhere.  If you're not sure, try 4-5 and
6-20 on the unspecified serial port end.  If you're using modem control
port names, it's 6-8-20.

Quote:>Any advice on how best to troubleshoot this one would be much
>appreciated. Are there any tools/testers available to
>detect "chatter"ing terminals?

The last time I did this was 7 years ago, so the memory is a bit foggish.
I wish I had some kind of utility that displays CLIST consumption.
u386mon does not display CLIST consumption.  That leaves "crash".

The rule-o-thumb for NCLIST is 10ea per tty serial connection including
multi-sessions.  So, if you're using mscreen, discreen, or Faceterm, you
need to include those sessions.  Also include serial printers.  The
buffers are small so a large number is no problem.

OSR5 has nifty feature that prevents miswired serial devices from
becoming a nuisance, but may hide the problem.  In the boot(F) man page,
the parameters:

INHIBIT=n
     If an inittab entry is respawned SPAWN_LIMIT times within
     SPAWN_INTERVAL seconds, init will not try to
     respawn that entry for this many seconds (unless a ``telinit q''
     is done). The default value is 300 seconds (five minutes).

SPAWN_INTERVAL=n
     If an inittab entry is respawned SPAWN_LIMIT times within
     this amount of time (seconds), init will not try to
     respawn that entry for INHIBIT seconds (unless a ``telinit q''
     is done). The default value is 120 seconds.

If these were reduced to a much smaller number, your flakey serial port
might be easier to troubleshoot as the problems will appear more often.

In my limited experience, having getty running on a serial printer port
can cause CLIST overflow.  I don't understand why this should be, but one
such problem was caused by this.  However, garbage pickup, due to
unterminated inputs and wiring errors was far more common.  The modular
plug to DB25 adapters were the major culprit with creative wiring as a
close second.

Good luck.

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